Speed-changing device.



No. 803,810. PATENTED NOV. 7,1905. G. A. CUTTER. SPEED CHANGING DEVICE.

APPLICATION FILED J UN B 24,1903.

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N0- 808,810. PATENTED NOV. 7, 1905.

G. A. CUTTER. SPEED CHANGING DEVICE.

APPLICATION FILED JUNBM, 1903.

4 SHEETS-SHEET 2.

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No- 803,810. PATENTED NOV. 7, 1905.

G. A. CUTTER.

SPEED CHANGING DEVICE. APPLICATION FILED JUNE 24.1903.

I. I S a 9% R I N w e 6 @Q 2 ill wimwoeo PATENTED NOV. 7, 1905.

' G. A. CUTTER. SPEED CHANGING DEVICE.

APPLIGATION FILED JUNE 24,1903.

4 SHEETS-SHEET 4.

UNITED STATES PATENT OFFICE.

SPEED-CHANGING DEVICE.

Specification of Letters Patent.

Patented Nov. 7, 1905.

Application filed June 24. 1903. Serial No. 162,955.

To v7 Whom, it may concern:

Be it known that I, GEORGE A. CUTTER. a citizen of the United States ofAmerica, residing at Nashua, in the county of Hillsboro and State of NewHampshire, have invented certain new and useful Improvements in Speed-ChangingDevices, of which the following is a specification.

The object of this invention is to produce devices of the generalcharacter herein'described having features of novelty and advantage.

Referring to the drawings, Figure 1 is a general plan view of anembodiment of my invention. Fig. 2 is a detail edge view of the belt.Fig. 3 is a detail plan view of the belt. Fig. 4 is a cross-sectionalview of the belt. Fig. 5 isaplan view ofainodilied form of belt. Fig. 6is an edge view of the same. Fig. 7 is a cross-sectional view of thesame. Fig. 8 is a general view of an embodiment of my inventionpermitting double reduction or increase.

The general features of the construction and operation of a device madeaccording to my invention are illustrated in Fig. 1, wherein a b are thetwo shafts, suitably supported,

is not movable with respect thereto.

from one of which, as a, it is desired to transmit power to the other,Z2. and provide for varying the speed of the shaft Z), while that of theshaft a is constant. For the purposes of a simple illustration of theinvention these two shafts are shown as mounted in the frame 0; but itwill be readily understood that the application of my invention topractical uses is not confined to such a structure as is illustrated. Onthe shaft a are mounted the two disks 0 a The disk at is keyed to theshaft, but is free to slide thereon toward and away from the disk a Thedisk (4 is keyed and pinned to the shaft so that it cannot be moved inany manner relatively thereto. On the shaft 6 are mounted the disks 6' bthe disk 6 being keyed to the shaft, but adapted for movement lengthwisethereof toward and away from the disk Z2 while the disk 6 is both keyedand pinned to the shaft, so that it The disks a a on the shaft (0 and bb on the shaft 6 constitute a peculiar form of driving-pulley, thecenter line between one pair of disks being coincident with the centerline between the other pairof disks, the pair ofdisks being connected bya suitable belt, as indicated at d. It will be seen from the drawingsthat the fast disk 64 on the shaft is diagonally is the shaft at.

opposite the fast disk o on the shaft 6. their active surfaces facingone another, and that the loose disks (4' b have the same relativepositions with respect to one another as do the disks a 6 A rod 6 ismounted to move across the frame 0 and has secured to it the arms 6 6which butt against and may be secured to the heads of the movable disks(4' 6. Means. as the worm-wheel and pinion 0 9*, are provided for movingthe rod 6 back and forth. It will be seen when this rod moves to theleft the disk I) is moved toward the disk and the disk (4 is moved awayfrom the disk 1 and that when the rod 6 is moved in the oppositedirection a is moved toward a and 5' away from A suitable belt-passesaround the two pulleys formed by the disks, it being provided on itsedges with active faces which engage the surfaces of the disks, whichwill be more clearly described hereinafter. The opposing surfaces of thedisks are spherically convex, as shown. Assuming that a is thedriving-shaft and b the driven shaft, it is evident that when thedistance between the disks (6 a Z) 6 is the same the two shafts will bedriven at the same speed, but that when the disk (4 is moved toward oraway from the disk a the shaft 6 will be driven at a faster or slowerrate of speed than It will be seen that as the position of the beltchanges in moving toward the larger diameter of one pair of disks andthe smaller diameter of the other pair its line of travel is shiftedfrom left to right, owing to the fact that one disk on each shaft isstationary with respect to the shaft. Be tween the disks (4 a I locate awheel or pulley a which is loosely mounted upon the shaft (0. When thedisk a is moved away from the disk a to a certain extent, the belt willrest upon the wheel (0 its active faces being disengaged from the disks(0 a and under these conditions the driving connections between theshafts a and 'Z) is interrupted, permitting the shaft 5 to remain idleduring the rotation of the driving-shaft a. This is the position of theparts as illustrated in Fig. 1. This pulley, in connection with thedisks and belt, furnishes a very efficient friction-clutch, it beingadapted for use to start a machine at its slowest speed from acontinuously-running shaft and to increase its speed gradually, asdesired.

For use in connection with a device of this kind 1 have produced a novelform of belt, which has many advantageous features. Re-

LOO

ferring to Figs. 2, 3, and 1, it will be seen that the belt thereinillustrated is in general of the form of an ordinary sprocket-chain. Asseen in Fig. 3. the side links for a certain part of their depth arebutted together, as at Z, which prevents its bending in one direztionand allows of its bending in the other direction. This feature preventsthe sagging of the chain in its travel from top of one pulley to the topof the other. To the side links are pivoted shoes Z, whose faces areshaped to fit closely upon the active surfaces of the driving-disks. Asillustrated, these surfaces are of a spherically-concave form adapted tolit on the spherically-convex disks. (Shown in Fig. 1.) The pivot ofthese shoes and the shaping of their active faces permits them readilyto accommodate themselves to such a position with respect to thedriving-disks that the most intimate and firm driving contact isobtained. As shown in Fig. 3, these shoes Z are pivoted to lugs Z formedon the side links, and they are held in position and agai st rattling bysprings Z In the modified form of belt shown in Figs. 5, 6, and 7 Iemploy an ordinary fiat belt 0, to which is secured at intervals thestrips 0' 0 at the ends of which I pivot the shoes 0 holding them inposition by the springs 0, the free ends of which are positioned by thepins 0 In other respects the belt and its mode of operation is similarto that shown in Figs. 2, 3, and 1.

Fig. 8 showsa duplication of Fig. 1, wherein .9 may be considered thedriving-shaft and t the driven shaft; 1), an intermediate shaft betweenthe two, which shaft is provided with suitable disks, one of each pairbeing fast to the shaft and the other keyed to, but movable lengthwisethereof. On the shaft 41 the fast disks o v are opposed to one anotherand the movable disks e c are preferably connected to a singleshifting-lever in such manner that when one is moved toward its coactingdisk the other is moved away from its coacting disk. It will be seenthat the reduction or increase between .9 and t is by this arrangementdoubled. An advantageous feature which is obtained by my constructionwhich permits of this double reduction is that the end thrust on thedisk 0 is balanced by that on the disk 4f, the same being true of themovable disks 0' Q1 thus relieving the mechanism and its supports whenused in this manner from any undue strain.

1 claim as my invention 1. A speed-varying device comprising expansiblepulleys having spherically-convex active faces, the shafts on which saidpulleys are mounted, and the belt connecting said pulleys, substantiallyas described.

2. A speed-varying device comprising expansible pulleys havingspherically-convex active faces, the shafts on which said pulleys aremounted, the belt connecting said pulleys, 5

GEORGE A. CUTTER.

Witnesses:

B. A. PEAsE, L. F. PEASE.

